The global read-only scheduler
property is the entry point for using the Prioritized Task Scheduling API.
It is implemented by both Window
and WorkerGlobalScope
. The existence of the property indicates that the API is supported in the current context, and can be accessed using this.scheduler
.
The object has a single instance method Scheduler.postTask()
that is used to post prioritized tasks for scheduling.
The code below shows a very basic use of the property and its associated interface. It demonstrates how to check that the property exists and then posts a task that returns a promise.
if ("scheduler" in this) {
const myTask = () => "Task 1: user-visible";
scheduler
.postTask(myTask)
.then((taskResult) => console.log(`${taskResult}`))
.catch((error) => console.log(`Error: ${error}`));
} else {
console.log("Feature: NOT Supported");
}
For comprehensive example code showing to use the API see Prioritized Task Scheduling API > Examples.